1. Field of the Invention
The present invention relates to a halogen-free flameproof mesh sheet used outdoors such as a construction site for a long time.
2. Prior Art
In recent years, there has been a trend toward the construction of buildings having a large number of stories in the construction industry. Meanwhile, there has been an increase in the number of houses having a small number of stories. Flameproof mesh sheets for safety and protection and scattering prevention flameproof mesh sheets must be laid in these buildings and regulations are becoming more and more strict.
Currently, used flameproof mesh sheets and scattering prevention flameproof mesh sheets are produced by weaving yarn prepared by coating a polyester, nylon or polypropylene multi-filament fiber with a vinyl chloride-based paste resin composition and heating and then heating the obtained cloth and by coating a fabric prepared by weaving and processing a multi-filament fiber with a vinyl chloride-based paste resin composition, heating and processing to a desired shape, respectively.
A vinyl chloride containing chlorine is used as the resin composition for coating a fiber and fabric. Illustrative examples of the flame retardant include chlorine-based flame retardants such as chlorinated paraffin, bromine-based flame retardants such as decabromodiphenyl oxide, and inorganic flame retardants such as antimony trioxide (Examined Japanese Patent Publication Nos. 52-41786, 53-18065 and 61-94305, Plastics, February, 1991).
In recent years, it has been globally demanded to avoid the use of resins and flame retardants containing elemental halogen which generates harmful gas at the time of combustion from the viewpoint of the environmental preservation of the earth.
Japanese Laid-open Patent Application No. 61-223045 proposes that red phosphorus and ammonium polyphosphate are kneaded into polyolefin to prevent corrosion by halogen contained in a halogen-containing compound flame retardant. However, there is unknown a flame retardant which is dispersed in an aqueous dispersion of a polyolefin resin.
In view of the above situation, it is an object of the present invention to provide a flame retardant for halogen-free flameproof mesh sheets which does not generate harmful halogen gas at the time of combustion and a flameproof mesh sheet comprising the same.
The present invention relates to:
A flame retardant for mesh sheets comprising about 1.5 to 15 parts by weight of red phosphorus and about 10 to 70 parts by weight of an ammonium polyphosphate compound based on 100 parts by weight of a solid content of an aqueous dispersion of a polyolefin resin having a resin solid content of about 20 to 45 wt %.
The polyolefin resin of the aqueous dispersion of a polyolefin resin may be selected from ethylene-methacrylic acid metal ion crosslinked copolymers and ethylene-based xcex1-olefin copolymers.
The polyolefin resin of the aqueous dispersion of a polyolefin resin may be a mixture of about 90 to 10 wt % of an ethylene-methacrylic acid metal ion crosslinked copolymer and about 10 to 90 wt% of an ethylene-based xcex1-olefin copolymer.
The red phosphorus and ammonium polyphosphate can be micro-encapsulated.
The flame retardant can further comprises about 60 to 150 parts by weight of a metal hydroxide based on 100 parts by weight of the solid content of the aqueous dispersion of a polyolefin resin. The metal hydroxide can be magnesium hydroxide and/or aluminum hydroxide.
The flameproof mesh sheet can be prepared by impregnating with the flame retardant, heating, and woven.
The flameproof mesh sheet can have an equivalent single fineness of a multi-filament fiber of about 3 to 17 denier, a total fineness of about 1,000 to 4,500 denier, a tensile strength of about 6 to 10 g/denier and a break strength of about 14 to 45%.
The flameproof mesh sheet can be coated by impregnating a mesh sheet fabric woven of a multi-filament fiber with the flame retardant for mesh sheets and heated.
The flameproof mesh sheet can be prepared by paralleling 1 to 4 synthetic fibers having an equivalent single fineness of about 2 to 13 denier, a total fineness of about 150 to 2,500 denier, a tensile strength of about 6 to 10 g/denier and a break strength of about 14 to 45% and leno weaving with a weaving machine and has a mesh length of about 10 to 140 warps/10 cm and about 10 to 140 wefts/10 cm.
The flameproof mesh sheet may be used in an amount of about 60 to 350 parts by weight based on 100 parts by weight of the multi-filament fiber or the mesh sheet fabric woven of the multi-filament fiber to coat the mesh sheet fabric by impregnation.